The electronics part is finished! Yesterday, I solved the 'crazy' motor issue. So now I can print air as the whole thing is not assembled yet and is still laid out my desk.
To be honest I got some help on solving the 'crazy motor' issue. It turned out I hadn't defined the bed center in Slic3r to match a Rostock Delta type 3D printer. The correct setting for a Rostock is 0x0 instead of the default 100x100 which is ok for Mendel, Prusa and the like. Combining 100x100 with a Rostock results in negative square root calculations and in the 'crazy motor syndrom'.
Now it's just waiting for the the plastic parts, rods and braided line to arrive. In the meantime I will prepare all parts for the frame.
Still looking for a good PTFE supplier for my bowden setup though.